51 year old Arunachalam Chrishanthakumar was given a shopping list of goods to be sent to Sri Lanka by the Tamil Tigers, The Telegraph reports.
These included computers, electrical goods and high-powered torches, which could have been used by fighters, although other items including speed guns were for the civilian administration of the part of Sri Lanka, ruled by the LTTE. The items did not include guns or explosives.
Jonathan Laidlaw QC, prosecuting, said he procured equipment for the group with an 'obvious terrorist purpose'.
Justice Saunders said: "This was a protracted, deliberate breaking of a law. These are very serious offences, which warrant substantial sentences. The terrorist law has to be obeyed as part of our obligations internationally."
But the judge decided the case was 'exceptional' as, at the time the offences were carried out, the Tamil Tigers were not banned in Sri Lanka and peace negotiations were taking place.
He paid tribute to the defendant's 'humanitarian' work, which he said he hoped would continue once he had completed his sentence.
The defendant, known as Shanthan, was born in Sri Lanka but moved to London and became a prominent figure in the Tamil community.
He was convicted by a jury at Kingston Crown Court of receiving electrical components for terrorism and a second count of receiving documents for terrorism, The Telegraph reports.
These included guides to underwater warfare systems, explosive ordnance disposal and mine clearance.
"He did not know and was not concerned whether the goods he supplied were to be used for civilian or military uses. He was given an order by the LTTE and he fulfilled it," said the judge.